First off, I am a self-identified weather geek. I have loved the weather since 5th grade and did my 6th grade science project on weather. I went on to be a research meteorologist at NASA, president of the American Meteorological Society, and director of the University of Georgia’s Atmospheric Sciences Program (currently). Heck, I even host a show on the Weather Channel called “Weather (Wx) Geeks. I point these things out to say that I completely understand the enthusiasm of the solar and astronomy community. You should see some of the weather debates about storm chasing, the best weather model, or the use of relative humidity rather than the dew point. Such passion shown by my colleagues is similar to the understandable excitement that eclipse watchers must feel. As someone external to that field, I am genuinely excited about it and have devoted three discussions to it.

Yes, absolutely there is a difference between viewing the eclipse at 100 percent totality versus something less. Eclipse2017.org has an excellent website discussing the difference between magnitude and obscuration. Obscuration is defined as the percentage or fraction of the sun’s area being covered by the moon at a given point in time. Magnitude is the fraction of the sun’s diameter being covered by the moon. At this point, you may be saying, “this is why scientists confuse me, what’s the difference?” The website goes on to point out

Obscuration has to be equal to 1 if all of the Sun is covered…..Magnitude during totality is always going to be bigger than 1. I don’t know if it makes any more sense to talk about being able to cover more than 100% of the Sun’s diameter than its area, but that’s what people do.

Ok, what this all means for the public is that some places will NOT experience 100 percent totality. Many people (including us in Athens, Georgia) will observe something less than that but still a very cool experience. At 99.1 percent totality, the experience is different.

Although a 99% partial eclipse is impressive, it is not 99% of the experience of a total (100%) eclipse. The sun is so bright that even with only 1% showing, it gives us 10,000 times the light of the full moon.

In Athens, Georgia, for example, we will not see a completely dark sky or the corona (area of plasma surrounding a star). The NASA graphic above gives you an idea of what you may see at your location. Pittsburgh-based physicist Fred Bortz is planning to drive into the path of totality. Dr. Bortz, an author of several children's science books, messaged me

In Athens, you will miss what I am hoping to see. The umbra sweeping across the ground at 1455 mph. I hope I have a good vantage point.

The moon’s limb is not perfectly smooth because of the mountain ranges and canyons that pepper the moon’s circumference as viewed from Earth. Shortly before the moon fully blocks the disk of the sun during a total solar eclipse, flashes of light can often be seen around the circumference of the moon’s blackened disk. These are caused by sunlight passing through the canyons around the limb of the moon. The namesake for these ‘diamond ring’ flashes is Francis Baily; a prominent English astronomer and four-time president of the Royal Astronomical Society.

I absolutely encourage anyone that can experience 100 percent totality to do so. While that is the optimal outcome, many people just cannot afford to do that or do no have the time:

Disadvantaged inner-city or rural children

Lower income families

Students (schools are back in session in Georgia where I live and at The University of Georgia on August 21st)

Sick and shut-in

Some kids will hop in the car with their families and head to the path of totality. They might even stay in one of the many over-booked hotels along the way. Other kids will be thinking about more basic needs on that day but still should be able to learn from the rare event without feeling "not good enough" because they could not get to the path of totality.

Teachable moments are opportunities to stimulate or nurture interest in science. We should be careful not to downplay the experience for those that will not see the full “awesomeness” of this shadow dance. It is exciting to see K-12 schools and the public preparing for the eclipse.

Total solar eclipse with corona.National Aeronautics and Space Administration

Dr. J. Marshall Shepherd, a leading international expert in weather and climate, was the 2013 President of American Meteorological Society (AMS) and is Director of the University of Georgia’s (UGA) Atmospheric Sciences Program. Dr. Shepherd is the Georgia Athletic Associatio...